Method and means for pumping in heat exchange applications

ABSTRACT

Equipment comprising a pump or fan embodiment arranged for connection to a heat exchanger where heat transfer between two media flows is effected by means of co-rotating surfaces. Cavities and rotating disc surfaces are stacked at different levels along a rotating shaft and heat exchange takes place from one level along the rotating shaft to another level. In a counter-flow heat exchanger one of the medias can, from a center channel inlet, enter a cavity between two rotating disc surfaces and then passing the cavity exit the cavity in radial slots at the periphery between two disc surfaces.

The present invention relates to ways and means to arrange pumping of medium, liquid or gases through a heat exchanger, which can have design to what is described in European patent 0586402 or another equipment, where powerful pumping of the media is acquired to the heat exchanger and also pumping from the heat exchanger. The invention also relates to embodiment of the method, consisting of a rotating part comprising internal cavities that provides pumping and transport of gases or liquids. One example of such applications where such pumps can be used are heat exchanger system in climate units for cooling of telecom stations or heat exchangers in heat recovery systems for real estates, cooling in climate units or other applications where pumping of two fluids, gases or liquids should be obtained in heat exchanger applications with high requirements of pressure performance.

It is easily understood that any type of pumping in varying heat exchange applications is a possible usage of the invention.

STATE OF THE ART

It is known, by European patent 0586402, that heat exchanger can be arranged by embodiment with rotating disc surfaces and cavities between the disk surfaces such that heat exchange occurs between two or more medias, flowing in the cavities. Heat Exchange occurs, by heat transfer, from one medium to the other through the disc surfaces. Primarily patent EU 0586402 embodiment or similar embodiments are characterized by cavities and rotating disc surfaces stacked at different axial levels along a rotating shaft. Heat-exchange basically occurs from one level along the rotating shaft to another level. The intention is that the media for each level with cavities can move along the disc surfaces basically in cavities. In an implementation of a so called counter-flow heat-exchange, said embodiment could be implemented in such a way that one media has a media-flow that, from the center channel inlet, enters a cavity between two rotating disc surfaces and, after passage of the cavity, exits the cavity in radial slots at the periphery, between two disc surfaces.

The other media flow enters another cavity, at another location along the rotating shaft between rotating disc surfaces from inlet channels arranged at the periphery and leaves the cavity in sector channels arranged in the center of the disc surfaces. This media flows if the complicated rotating fluid mechanical movement in the cavity is disregarded mainly from the center and radially outward towards the periphery along the disc surfaces and leaves the rotating heat exchanger in radial slots at the periphery. This flow is pumped out of the heat exchanger itself and for most cases does not need any further pump or fan device.

The other media flows, if the complicated rotating fluid mechanical movement is disregarded, mainly from periphery and radially inwards towards sector channels in centre, in cavities between disc surfaces. This media or flow that passes from the periphery and towards the centre in the heat exchanger cavities has large pressure drop. It needs some highly efficient pump or fan device to overcome this pressure drop and make flow through heat exchanger possible.

A pump or fan wheel with the same diameter as the heat exchanger on the same shaft as the heat exchanger that has the same speed of rotation as the heat exchanger can not according to any known pumping technology achieve enough pumping pressure head to overcome the pressure drops for the passage in the heat exchanger cavities for commercially used flows in the heat exchanger.

To achieve enough pumping capacity or so called pressure head for commercially used flows, a pumping wheel on the same shaft as the same heat exchanger must either have much higher speed of rotation, which is mechanically very complicated or be designed with much larger diameter, which require larger volume for the whole heat exchanger.

One third way is to arrange two pumping wheels which make pumping in series after each other or one pump before and one after passing the heat exchanger, which requires much bigger volume and makes the pumping system volume comparable with the heat exchanger as a whole. This reduces the advantages with heat exchanging according to patent EU 0586402.

One fourth alternative is to have external pumping facilities to overcome the pressure drops, which also requires much bigger volume, requires much more apparatus and equipment and makes total system volume much bigger and costly, which reduces the advantages with heat exchanging according to patent EU 0586402.

SUMMARY OF THE INVENTION

The intention of the present invention is to eliminate the drawbacks listed above for pump or fan device in counter flow heat exchanger systems according to European patent EU 0586402 or similar, for the flow that passes heat exchange process in cavities between disc surfaces from periphery and radially inwards towards the center, with a method for pumping or as a pump or a fan device, that in one unit makes efficient pumping effect and pressure head for flow both before and also after passing the heat exchange process.

The solution is an embodiment according to the patent claims.

SHORT DESCRIPTION OF THE DRAWINGS

The present invention will be explanatory described utilizing different embodiments of the invention and referring to enclosed drawings, as follows:

FIG. 1 illustrating an embodiment of the present invention with a rotating part, in combination with heat exchanger according to patent EU 0586402 or similar heat exchangers, the invention is illustrated in a side view parallel with the fan or pump embodiments rotation axis.

FIG. 2 illustrating a pump or fan embodiment according to it's mainly parts. The parts are seen in views from beneath the rotating part in FIG. 1. At the top of the figure is the lid of the pump or fan embodiment. At the bottom is the pump or fan embodiment bottom. In between is a part with several cavities and barriers connecting lid and bottom. In this figure the two medium flows is also illustrated.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The, in the text, so called pumping embodiment or device means both fan and pump embodiment or device. Medium means all types of fluids that can be gases or liquids where any of the gases can be air.

In FIG. 1, an embodiment of a heat exchanger according to patent EU 0586402 or similar embodiments provided with the pump device according to the present invention is shown. The heat exchanger comprises a rotating part 1 being symmetrical in rotation that can be revolved around an axis of rotation 2 by means of driving of an electrical engine or another driving arrangement. The rotating part 1 consists of a package with several similar discs and stacked to each other axially along a shaft with cavities between discs. The cavities in rotating part 1 communicate mutually such that they altogether are separated in two different volumes separated from each other. One fluent medium in one volume cannot go into the other volume inside the heat exchanger package in rotating part 1. Two different mediums can then be kept separated from each other in the rotating part 1.

One of the flows enters in sector channels in centre of rotating part 1 and passes in each other cavity axially and leaves the heat exchanger at the periphery of rotating part 1. This flow can be ignored for the innovation of the pump embodiment or device.

The other flow medium 3 that in the stack of heat exchanger enters the other cavities at the periphery passes the heat exchangers cavities mainly radially inwards towards the centre of the rotating part 1 and leaves the cavities in channels in the centre, which are connected to the special pump embodiment 16, intended as the invention.

The medium 3 has, after heat exchange, thermodynamically changed its condition when it leaves the heat exchanger channels in the centre. It is then called medium 4.

FIG. 2 shows the pump or wheel embodiment 16 earlier described with the different parts in views along rotational axis and from points beneath the rotating part 1 in FIG. 1. It consists of a lid 6, middle part with barriers 8, 9 and 19 and bottom part 10. The barriers 8, 9 and 19 connect lid 6 and bottom 10 axially along rotational axis 2. Medium 3 is sucked into the pump or wheel 16 through sector holes 5 near the centre of the lid 6. The medium 3 is brought to rotate in cavities 7 by force from barriers 8 and 9, which gives a pumping effect of medium 3 before it leaves pump and flows to openings 18 and enters into axial channels at the periphery of the heat exchangers stack in rotating part 1.

The cavities 7 are enclosed between the pumping wheel lid 6 and radially formed or almost radially formed walls 8, 9 and barrier 19 at the periphery and also pumping wheel bottom 10, with exceptions of openings 5 and 18.

Naturally, a pipe system can also connect the sector formed holes 5 in the pumping wheel lid 6 and the axial channels 18 in pumping wheel bottom 10 with similar physical effect regarding fluid dynamics and pumping effect.

The turbine formed vanes for the walls 8 and 9 according to FIG. 2 can be replaced by a straight radial form or another curved form. The conditions for fluid dynamics and speed of rotation will determine what curve form that is the most optimal for the special case.

FIG. 2 shows also how medium 4, the medium that is heat exchanged in heat exchanger stack in rotating part 1, enters pump or fan 16 from heat exchanger through sector formed openings 11 in the centre of bottom 10. It is further guided in cavities 12 to be brought to rotation by force from barriers 8 and 9 once more and leaves the pumping wheel through pump or fan wheel openings 13 at the periphery. Medium 4 gets with this bringing to rotation, so called pressure head, which also contributes to the sucking capacity of medium 4 from the centre channels 11. Barriers 8, 9 and 19 between lid 6 and bottom 10 prevent that medium 4 is mixed with medium 3.

As can be seen from FIG. 2 the medium 4 gets its force to rotation from the sides of barrier 8 and 9 which is exposed to cavity 12. The medium 3 gets its force to rotation from the sides of barrier 8 and 9 which is exposed to cavity 7.

The space 14 in FIG. 1 with medium 4 flowing from rotating part 1 is kept separate from the space 15 outside rotating part 1 by a sealing 17 between rotating part 1 and stator parts 20 outside rotating part 1. This sealing 17 is a barrier between the spaces 14 and 15 and connects with no gap, a small gap or very small gap between rotating part 1 and the stator parts 20 that are radially outside rotating part 1.

A similar sealing 21 FIG. 1 exists between inlet to the pumping wheel lid 6 and the stator 20 around the pumping wheel 16 and rotating part 1. The purpose of this sealing 21 is to separate medium 3 and medium 4 from each other, actually the same medium that has changed thermally condition. The sealing 21 can be of the same type as 17.

Examples of sealings for both 17 and 21 can be in the market existing common axial seals, radial seals, lip seals, labyrinth seals or another form that combines a rotating part with a stator part. It shall a accomplish separation between spaces for different mediums around rotating parts.

The combined pumping effect on the inflow to the heat exchanger and pumping effect of medium 4 out of heat exchanger in rotating part 1 according to pump or fan embodiment in FIG. 2 gives together much larger pumping effect than with only one of said effects. With this type of pump or fan embodiment described in this invention double functioning pumping effects are achieved with only one pumping embodiment or wheel, which can overcome the high pressure drops that occurs in this type of heat exchanger in rotating part 1.

As described earlier necessary pumping effect to overcome pressure drop in this type of heat exchanger can be made in other ways by for example two separate pumps or fan wheels on the same shaft and with the same speed of rotation as the heat exchanger, one for pumping before the heat exchanger and one for pumping out from the heat exchanger.

This should however need considerably large volume relative the heat exchanger volume. The two pump wheels with the same diameter as the disc stack in rotating part 1 should require more than 50% of the volume of the disc stack in the heat exchanger.

With two pumping wheels connections to the heat exchanger should also be needed that also increases total system volume. Exactly how the connections to the heat exchanger should be done in that case is not known. The advantages with heat exchanger system based on patent EU 0586402, which is to be considerably more volume effective than conventional existing heat exchanging systems, should then be reduced.

The properties of the invention makes it possible that pump or fan wheel embodiment 16 with its double functioning pump effect can make the intentional pumping effect that is required for this type of heat exchanger in only one pump or fan wheel 16. With the described arrangement of the pumping wheel, big advantages are achieved with design that is much more volume effective than with two pumping wheels. The pumping wheel 16 has also less details and is also simpler to produce than two separate pumping wheels which also reduce cost for the total design.

One other property and advantage with the described invention is that inflow of medium 3 into the rotating part 1 to the heat exchange system according to EU 0586402 can in a very simple way be arranged in the same part of the stator enclosure 20 to the heat exchanger according to FIG. 1 to its lower part.

The inflow of medium 3 goes to the centre hole in stator enclosure 20. The outflow of medium 4 goes also out in the lower part of stator enclosure 20 and can be separated from the environment and among that the medium which the heat is exchanged to. It is necessary for certain heat exchange applications, for example cooling of outdoor telecom stations where separation from outdoor environment is necessary for the air that is inside the station. With that arrangement complicated channel systems outside the heat exchanger system can be avoided.

The invention is not limited only for use connected with heat exchange according to patent EU 0586402 or similar embodiments. The described invention can also be used where pumping to medium flows is needed in the same rotating unit. The described embodiments with sealings 17 and 20 which are described between the rotating pumping wheel and the stator enclosure 20 is an essential to separate the two media flows and eventually other environmental medium of other kinds. The various described and shown embodiments, but variations thereof are naturally possible within the scope of claim 1. 

1. A method of pumping media in heat exchangers with rotating disc surfaces and cavities between the disc surfaces in a cylindrical housing, for the flow that passes heat exchanger process, entering cavities between heat transfer surfaces at the periphery and exits the cavities through channels in centre of heat exchanger in several parallel cavities which are formed between said surfaces in the cylindrical housing, whereby no leakage occurs between said surfaces and the cylindrical housing, causing the major part of the flowing medium to pass through a rotating flow-mechanical boundary layer adjacent to the rotating transfer surface in lamellar or turbulent flow, said medium or media is introduced to the periphery of the rotating surfaces with the medium or media already in rotation in the rotational direction of said surfaces, said discs are divided into sections by means of partition walls so constructed that said flow is delivered separated from the centre to the periphery, and subsequent to passage over the rotating disc surfaces the flow leaves through channels in the center of the heat exchanger, characterized by that pumping is arranged in one or the same pump or fan embodiment with the same speed of rotation as the heat exchanger, connected to the heat exchanger and giving pumping effect by bringing to rotation the medium entering the heat exchanger and also giving pumping effect by bringing to rotation the medium that leaves the heat exchanger.
 2. A method according to claim 1 characterized by that medium (3), which shall enter the heat exchange process, enters in pump or fan through inlet openings (5) at the centre of the pump or fan embodiment and leaves the pump or fan through outlet openings (18) at the periphery axially connected to channels at the periphery into the heat exchanger.
 3. A method according to claim 1 characterized by, that medium (4), which has passed heat exchange process, enters pump or fan embodiment through an inlet openings (11) at the pump or fan equipment centre in the part that is connected to the heat exchanger centre of and leaves pump or fan through outlet openings (13) radially or axially in the periphery of the pump or fan.
 4. A method according to claim 2 characterized by that the medium (3) that shall pass heat exchanger process enters sector formed or nearly sector formed openings (5) in the lid (6) and passes to axial openings (18) at the periphery, for outlet of the flow from the pump or fan, in pump or fan bottom (10) connected to the heat exchanger and also for the flow of medium (4) that has passed through heat exchange process enters sector formed or nearly sector formed openings (11) in the heat exchanger and exits the pump or fan embodiment at openings (13) at the periphery of the pump or fan embodiment.
 5. A method according to claim 4 characterized by that the fan or pump embodiment separates the flow medium (3) that shall pass the heat exchange process, from the flow of medium (4) that has passed the heat exchange process with radial, curved formed from centre to periphery or turbine vane formed barriers (8) and (9) between lid ([beta]) and bottom (10) of the pump or fan embodiment and barrier (19) in the periphery of the pump or fan embodiment radially outside the outlet (18) for the axial channels for the medium (3) that shall pass the heat exchanger.
 6. A method according to claim 4 characterized by that the pump or fan equipment has a pipe system connecting the sector formed openings (5) in the lid of the pump or fan embodiment and the axial openings (18) in the bottom of the pump or fan embodiment connected to axial channels in the heat exchanger inlet.
 7. A device for pumping media flow in heat exchangers, with rotating disc surfaces and cavities between the disc surfaces in a cylindrical housing, for the flow that passes heat exchanger process, entering cavities between heat transfer surfaces at the periphery and exits the cavities through channels in centre of heat exchanger in several parallel cavities which are formed between said surfaces in the cylindrical housing, whereby no leakage occurs between said surfaces and the cylindrical housing, causing the major part of the flowing medium to pass through a rotating flow-mechanical boundary layer adjacent to the rotating transfer surface in lamellar or turbulent flow, said medium or media is introduced to the periphery of the rotating surfaces with the medium or media already in rotation in the rotational direction of said surfaces, said discs are divided into sections by means of partition wall so constructed that said flow is delivered separated from the centre to the periphery, and subsequent to passage over the rotating disc surfaces the flow leaves through channels in the centre of the heat exchanger, characterized by that the pump device is arranged in one or the same pump or fan unit with the same speed of rotation as the heat exchanger and connected to the heat exchanger, which has means by bringing to rotation giving pressure head to the medium entering the heat exchanger and also has means by bringing to rotation giving pressure head to the medium that leaves the heat exchanger.
 8. A device according to claim 7 characterized by that the pump or fan device has a lid (6) not connected to the heat exchanger with sector formed or nearly sector formed inlet openings (5) for medium (3) that enters heat exchange process and a bottom (10) with outlet openings (18) for medium (3) at the periphery for passage to heat exchanger and sector formed or nearly sector formed inlet openings (11) for medium (4), outlet openings (13) for medium (4) at the periphery, curved formed from centre to periphery or turbine vane formed barriers (8) and (9) between lid (6) and bottom (10) that guides, brings to rotation and separates medium (3) and (4), and barriers (19) radially outside outlet openings (18) between lid (6) and bottom (10). 